"use strict";

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.default = getScrollTop;
/**
 * 兼容性封装
 * 滚动条在Y轴上的滚动距离（被卷去的距离）
 * @param targetElement 可以指定目标元素
 * @returns {number}
 */
function getScrollTop(targetElement) {
    var scrollTop = 0,
        bodyScrollTop = 0,
        documentScrollTop = 0;
    if (targetElement) {
        scrollTop = targetElement.scrollTop;
    } else {
        if (document.body) {
            bodyScrollTop = document.body.scrollTop;
        }
        if (document.documentElement) {
            documentScrollTop = document.documentElement.scrollTop;
        }
        scrollTop = bodyScrollTop - documentScrollTop > 0 ? bodyScrollTop : documentScrollTop;
    }
    return scrollTop;
}